The advent of a practical solid state current limiting interrupter such as described in U.S. patent application Ser. No. 610,947 filed May 16, 1984 in the name of E.K. Howell has provided a synergistic relationship between the circuit interrupter contacts and the contact operating mechanism. By employing a solid state switch in parallel with the contacts, the current is diverted away from the contacts immediately upon contact separation to substantially reduce the arcing energy and hence essentially eliminate the deleterious arcing effect on the contacts. This in turn allows the contacts to be made much smaller and hence reduces both their thermal and inertial mass. The reduction in the inertial mass in turn allows the contacts to be more rapidly separated and hence allows circuit interruption during the early stages of the current wave form. The lower contact inertial mass allows the use of a bridging contact between a pair of fixed contacts such as described in U.S. Pat. No. 4,598,187, issued July 1, 1986, entitled "Current Limiting Circuit Breaker" in the name of E.K. Howell. The bridging contact arrangement provides for a further reduction in the mass of the contacts such that even more rapid contact separation can be attained and allows the current interruption to occur at the correspondingly earlier stages of the current waveform.
U.S. patent application Ser. No. 814,865, filed Dec. 30, 1985 and entitled "High Speed Contact Driver For Circuit Interruption Device", describes an extremely fast contact driver utilizing a balanced cantilever spring and a pair of spaced parallel conductors arranged to drive a bridging contact away from a pair of fixed contacts. The conductors are spaced within a pair of magnetic plates to enhance the electromagnetic repulsion generated between the conductors when a high current pulse is applied.
The aforementioned Patent Applications are incorporated herein for reference purposes and should be reviewed for a good description of the operation of a solid state switch for circuit interruption as well as for describing the configuration of a bridging contact arrangement. The instant invention is directed toward a high speed contact driver for rapidly separating a bridging contact from a pair of fixed contacts similar to that described in the latter referenced patent application Ser. No. 814,865.
U.S. Pat. No. 3,215,796 in name of Bruno Leisi, discloses the idea of utilizing line current to produce a varying magnetic field arranged around a pair of spaced parallel conductors to induce opposing currents within the conductors to drive the conductors apart and to separate movable contacts from associated fixed contacts.
U.S. Pat. No. 3,168,626 in the name of Richard Patrick, discloses a fuse utilizing the repulsive forces developed by fault currents flowing in opposite directions through closely spaced, parallel fuse links to sever one or both links and thus interrupt the faulted circuit.
U.S. Pat. No. 3,002,065 in the name of John LaTour, Jr., discloses the use of excessive line currents flowing in opposite direction through conductive columns to repulse one of the columns and thus provide a shunt path to protect a meter.
U.S. Pat. No. 1,720,566 in the name of Joseph Pestarini discloses a circuit controlling device which utilizes a magnetic force to enhance the electromagnetic separation of a bridging contact from a pair of fixed contacts.
U.S. Pat. No. 4,039,983 in the names of Claude Terracol et al. discloses a high speed circuit interrupter having both main contacts and arcing contacts. The main contacts employ a bridging contact for operation and the arcing contacts utilize electromagnetic forces to hold the arcing contacts closed for a short period of time after separation of the bridging contact from the main contact.
The purpose of the instant invention is to provide a high speed contact driver arrangement wherein a high current pulse is employed to electromagnetically repulse a pair of conductors serving as a contact carrier for a bridging contact arranged across a pair of contacts within a protected circuit for extremely fast circuit interruption upon command.